1. Field of the Invention
The present invention relates generally to articles of footwear, and in particular to a method for creating outsoles.
2. Description of Related Art
Methods for constructing a tread assembly, which is a set of tread elements fixed in place to a thin and flexible matrix lining, such as those used for shoe outsoles, have been previously disclosed.
Fram (U.S. Pat. No. 6,032,388) discloses a method in which an inelastic sheet material is provided with a pattern of perforations through it, and a plurality of tread elements are created. The sheet material is placed in a molding machine with tread forming cavities below the sheet material. Following this, tread material is injected into tread forming cavities. The tread forming material flows out of the tread forming cavities and through the perforated sheet material into molding, cavities that have been secured just under the sheet material. The tread is injected through the perforations in such a manner so that some of the resultant tread elements have anchoring portions extending through the sheet material from an opposite side of the material.
Hiraoka (U.S. Pat. No. 6,562,271) discloses a method in which a male and female mold are engaged with each other in order to form a nonslip member, composed of a base fabric and nonslip convexes. The nonslip convex includes a peripheral edge that reinforces anchoring between the nonslip convex and the base fabric. A plate-like material is inserted between the male and female molds, and by engaging these molds a large number of small pieces coincident to a shape of through holes of the female mold are punched out from a plate-like material. These small pieces are then bridged and fixed to the base fabric to serve as the tread of the nonslip member. This method of manufacturing tread elements includes several steps.
There is currently a need for a method for making a tread assembly that is more efficient, while at the same time, allowing for a great deal of variation or flexibility in terms of the composition of the material that will eventually compose the tread assembly. In particular, a method is needed that can reduce the number of steps used in manufacturing a tread assembly, even complex tread assemblies.